This invention relates in general to image sensing devices, and in particular to solid-state color image sensing devices.
U.S. patent application Ser. No. 959,830 entitled "Color Responsive Imaging Device Employing Wave-length Dependent Semiconductor Optical Absorption", filed Nov. 13, 1978 in the name of Burkey et al discloses a multiple, superposed-channel color image sensor wherein the differential absorption of light by a semiconductor material is employed to selectively sensitize a plurality of superposed light sensitive channels to respective bandwidths of illumination. One multiple, superposed-channel color image sensor is configured as a multiple, buried-channel charge coupled shift register having transparent transfer electrodes. The charge transfer cells of the shift register serve as a multiple, superposed-channel image sensing sites. Photocharges generated at the sensing sites and collected in respective superposed channels are simultaneously moved to a plurality of outputs by appropriately pulsing the transparent charge transfer electrodes. Respective channels "fan out" at an end of the register so that electrical contact may be made to buried channels by conductive columns of heavily doped semiconductor material. Such conductive columns, because of the depths to which they must penetrate into the substrate, are relatively difficult to manufacture. Furthermore, because each channel "fans out" in a different direction at the end of the shift register, separate masks are required for forming each channel, thereby increasing the design and fabrication costs of the device.